1. Field of the Invention
The present invention relates to an electric vacuum cleaner and more particularly to an electric vacuum cleaner that uses water as a filter to remove dust.
2. Prior Art
In one type of electric vacuum cleaner, air that is sucked in from a suction hose is forced to pass through water, thus removing dust contained in the air using the water as a filter. Such an electric vacuum cleaner typically includes, in its vacuum cleaner main body to which the suction hose is connected, a water pan and a suction compartment. The water pan stores water used as a filter, and the suction compartment sucks in air from the suction hose via the water stored in the water pan and discharges the air from which dust has been removed to the outside of the vacuum cleaner main body. The suction compartment generally comprises a suction fan which sucks in air and a separator which separates the water from the air passing through the water in the water pan and discharge only the dust-free air to the outside as is disclosed in, for example, Japanese Patent Application Laid-Open (Kokai) No. H11-32950.
Electric vacuum cleaners that remove dust from air using water as a filter have the advantage that they are efficient in removing the dust and they have high degree of cleanness of the discharged air. However, since the air is sucked in via water, they have some problems. The dust that is filtered out by the water and remains in the water pan adheres as a contaminant to the separator that is used to separate the water from the air. More specifically, the separator is typically a basket-form component, and numerous slit holes that open in the axial direction are formed in the circumferential direction; and this separator is rotated at a high speed by an electric motor when the vacuum cleaner main body is driven. Accordingly, when dust accumulate on the separator or the rotating shaft of the separator, a smooth rotation of the separator is hindered, the separator would become stuck, thus being unable to rotate.
One conceivable method to prevent the separator from being stuck is to introduce air into the interior of the vacuum cleaner main body so that such introduced air removes dust adhering to the separator and gaps between parts installed near the separator. However, since the external air that is introduced into the vacuum cleaner main body most likely contains dust, it cannot be said that the effect of this method to remove contaminants adhering to the separator and the interior of the vacuum cleaner main body is always sufficient.